Introduction
On 8 April 2011, a Piper PA-38-112 Tomahawk, registration G-OTFT, was involved in a ground incident at RAF Henlow, Bedfordshire. The aircraft, powered by a single Lycoming O-235-L2C piston engine, was stationary with the engine running at idle power when a passenger was struck by the propeller, resulting in serious arm injuries to the passenger. The pilot was uninjured.
The Accident
The aircraft had been taxied to a refuelling location near a fuel bowser. After the pilot shut down the engine, she went to the control tower to complete pre-flight preparation and collect a headset. Upon returning, she gave the passenger a pre-flight briefing before starting the engine. Noticing the passenger lacked a headset, the pilot instructed the passenger to retrieve it from the control tower and re-stated how to exit the aircraft and the route to follow. To protect the engine, the pilot reduced power to idle rather than shutting down immediately. As the passenger moved toward the front of the aircraft, the pilot knocked on the windscreen and pointed toward the rear, believing the gesture was seen. The pilot shut down the engine upon seeing the passenger step down from the wing.
Passenger's Account
The passenger, for whom this was to be the first flight in a light aircraft, reported receiving only initial briefing on stepping on the black walkway and fastening the seat belt. When asked to retrieve the headset, she was not told how to exit or the route to follow, nor to walk around the rear of the aircraft. Exiting onto the wing and closing the door, she saw the control tower ahead and walked toward it, staying on the black walkway. She stepped off the front of the wing and did not notice the propeller. She did not believe the pilot attempted to gain her attention.
Regulations and Guidance
Article 88 of the Air Navigation Order requires the commander of an aircraft to take reasonable steps to ensure passengers are aware of the position and method of use of safety equipment, but does not specify additional briefing for specific aircraft types. Safety Sense Leaflet 2, published by the CAA, advises pilots to emphasize that propellers are extremely hazardous, to shut down engines when passengers are boarding or leaving unless escorted by properly briefed helpers, and to advise passengers to approach or depart from behind the wing. It also states that even with the engine stopped, passengers should not step forward off the wing leading edge toward the propeller.
Discussion
The investigation did not reconcile the differences between the pilot's and passenger's accounts. The accident demonstrated the danger represented by propellers, highlighted the importance of pre-flight safety briefings, and reinforced points from Safety Sense Leaflet 2.